单项选择题
The primary function(s) of an automatic sprinkler system is(are) to（）.
A.extinguish the fire which triggers it B.limit the spread of fire and control the amount of heat produced C.protect people in the areas which have sprinkler heads D.alert the crew to the fire
单项选择题 The preferred type of pollution control for oil spills on the water is(are) （）.
单项选择题 The preferred agent used in fighting a helicopter crash fire is（）.
单项选择题 The outlet at a fire hydrant may be positioned anywhere from horizontal to pointing（）.
